MDL-29378 Fix the form display in the Survey/COLLES P+A module
In MDL-7501, we stopped using rowspanning cells in the form table due to
accessibility. That had introduced a regression so in the COLLES P+A survey,
all the rows were displayed with the same background colour. This patch returns
the previous behaviour that each couple of items can be distinguished by the
background colour.
Also, there is no need to display "I prefer that" and "I found that" as a small
text any more. It had made sense in rowspanning layout but not after MDL-7501
was fixed.
And finally, as all items are enumerated now sequentially, there are actually
48 lines, each couple covering one question in two variants. I think it's
correct to reflect this in the description of the form so the text was slightly
amended.
